The Consequences of Working the Night Shift

By Jeany Miller

Pulling an all-nighter is often a rite of passage for college students. Some professions also require these hours, such as a night shift nurse or assembly line worker. Sleep deprivation, however, is a real problem that can affect night shift workers. This is especially true when those hours become routine. In reality, night shifts are as unnatural as they are unhealthy, posing health consequences that cannot be ignored.

What the Experts Say

To understand normal sleep patterns, people first need to understand circadian rhythms. These are defined as physical, mental and behavioral changes that roughly follow a 24-hour cycle. Circadian rhythms serve as important factors in determining human sleep patterns. Although these rhythms are produced by natural factors within the body, they are also affected by signals from the environment, such as light. Circadian rhythms indirectly tell the body to produce more melatonin in the absence of light. Hence the reason people feel naturally drowsy at nighttime. Harvard sleep specialist Dr. Charles Czeisler states people can adapt to overnight work, but it is difficult. Not only does this defy human nature, but people who work nights tend to revert to daytime schedules on days off. Such flip-flopping can make it difficult for employees to stay alert at work. Another complication is the work environment itself. Today, people are not allowed to nap during night shifts, thus they remain continuously awake. At some point, Czeisler says, the brain takes control of the situation. People then pass from wakefulness to sleep without thinking, even in circumstances where this is forbidden or dangerous.

Health Complications

Although a person risks his or her job when falling asleep at work, health is jeopardized without that sleep. A 2008 study conducted by Scott Davis, University of Washington professor and chairman of Epidemiology, found risks for disease increase dramatically for those who work the graveyard shift. These diseases include gastrointestinal disorders and cancers of the breast, prostate and colon. Increased stress and adverse pregnancy outcomes are further consequences faced by night workers. Short term effects such as crankiness, loss of socialization and inability to meet work or study needs may also ensue. Davis suggests the only way to combat disease and/or mood problems is to protect daytime sleep hours as much as possible.

Another effect of sleep deprivation, heart disease, has also been determined. Researchers at Harvard Medical School conducted a study in which they found working the night shift might lead to hormonal and metabolic changes. Those changes can raise the risks for obesity and diabetes. "In the long run, the physiological impact of shift work on several markers involved in the regulation of body weight (leptin, insulin, cortisol) seems to contribute to the increased risk for the development of diabetes, cardiovascular disease and obesity," says study author Frank Scheer.

Scheer points out that around 8.6 million Americans perform shift work, which the National Sleep Foundation defines as any type of schedule that falls outside the standard nine-to-five norm for business hours. Complications from this work are believed to arise from a chronic disconnect between waking and eating habits demanded by the work and routine circadian rhythms. To test this theory, Scheer and colleagues conducted a laboratory test designed to mimic the effects of regular shift work. The bodily responses of five men and five women were tracked as they adhered to a 10-day schedule of constantly changing sleep and eat habits. The results showed circadian misalignment led to decreased levels of the weight-regulating hormone leptin. Obesity and heart disease were then hastened because of increases in appetite and decreases in activity. Changes in blood sugar and insulin levels also occurred. Because work schedules cannot be ignored, but biological responses cannot be changed, many researchers now suggest that naps be allowed during night shifts. Czeisler is an advocate for these, stating employees can drink and eat during breaks and should thus be able to nap as well. Those brief periods of sleep may make a great difference in the health of night shift workers.

Sources: http://www.reporternews.com/news/2008/apr/07/working-night-shift-can-have-consequences/

http://dailyuw.com/2008/1/16/what-you-need-know-about-working-graveyard-shift/

http://www.aviisha.com/article/working-night-shift-increases-risk-diabetes

http://www.sleepdisorderchannel.com/shiftwork/index.shtml

http://www.msnbc.msn.com/id/42633432/ns/health-behavior/t/odd-work-schedules-pose-risk-health/